#include <Arduino.h>
#include <Servo.h>

// put function declarations here:
Servo servo;
int servo_pin = 3;

void setup() {
  // put your setup code here, to run once:
  servo.attach(servo_pin);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i = 0; i <= 180; i++)
  {
    servo.write(i);
    delay(15);
  }
  for (int i = 180; i >= 0; i--)
  {
    servo.write(i);
    delay(15);
  }
}

// put function definitions here: